An ultrasonic doppler motion sensor device includes a transmitter (10, 12) for emitting a continuous ultrasonic transmission signal in a detection space, an ultrasonic receiver (20, 22) for detecting the ultrasonic transmission signal reflected by the detection object as a receive signal, and a mixer and detector (14, 18) for mixing the ultrasonic transmission signal or a signal derived therefrom with the receive signal and/or for demodulating the receive signal and for generating a motion detection signal therefrom, wherein the mixer and detector are assigned a system (14) for the adjustable generation of a phase shift greater than 0° between a phase of the ultrasonic transmission signal and a periodic impulse signal at the mixer or detector for scanning and mixing the receive signal.